Stroke is the fifth leading cause of death for Americans and a leading cause of serious long-term disability. Every year, more than 795,000 people in the United States have a stroke. Stroke kills more than 130,000 Americans each year, which is about 1 out of every 20 deaths. About 87% of all strokes are ischemic strokes, in which the blood flow to the brain is blocked. Stroke costs the United States an estimated $33 billion each year. This total includes the cost of health care services, medicines to treat stroke, and missed days of work.
Current approaches to treating ischemic stroke are primarily limited to the administration of thrombolytic therapeutics such as tissue plasminogen activator, or to an invasive endovascular procedure involving the use of a clot removing/retrieving device. Thrombolytic therapeutics, however, must be given during the first few hours of a stroke, are associated with a risk of bleeding, and are only useful for ischemic strokes, not for hemorrhagic strokes. The clot removing/retrieving device is applicable in less than 10% of embolic stroke cases. Thus, improved medical therapy for stroke, particularly ischemic stroke, is needed and represents an unmet area of need.